Raif

Hi all,I have a fuzz guitar effect pedal kit to build. I would like to replace its knobs (potentiometers) with digital potentiometers and control them with Arduino using SPI. Arduino coding and SPI implementations are more or less clear for me, but the problem is to find right digital potentiometers or some other solution to replace the potentiometers.

See the original fuzz diagram here.

The potentiometers to be replaced are:

P1: C5K

P2: A500K

P3: A250K

5K digipots are manufactured widely and 250K digipots with SPI can be found few. However I'm not able to find 500K digipots with SPI on the market. Are there such digipots available somewhere? Is there some other work around to replace the 500K potentiometer?

Just checked Mouser and RS. An alternative would be the use of i.e. H11F1M. These are linear optocouplers. Using the Arduino with PWM to control the optical side and using 2 in series. Would give you 255 positions after a lot of research though.